1unweleiinweleThe girl combed her hair — Intombazana yakama iinwele zayo
2(on a person's legs, arms, etc.)uboyaHe has thick hair on his arms — Unoboya obuninzi ezingalweni zakhe
3(hair on an animal)uboyaa dog with short hair — inja enoboya obufutshane
In English, you only use the plural 'hairs' when you are talking about separate hairs, as in 'I washed three hairs off the side of the bath'.